you're supposed to pull over immediately and change or fix the tire rather than riding on it...they are really only designed to help you steer after a catastrophic loss of pressure at high speed.

Maybe that's what you are "supposed" to do, but the reality is that BMW doesn't give us a spare in the car, or even a jack or lug wrench, so changing or fixing the tire on the side of the road really isn't an option.

ahhhh even after reading the whole thing i am still little bit skeptical about it, i mean each car has to have different RFT's, like z4 and x5 has to be different, then ALL they REALLY fixed was the harsh ride quality, but nothing performance wise.

Maybe that's what you are "supposed" to do, but the reality is that BMW doesn't give us a spare in the car, or even a jack or lug wrench, so changing or fixing the tire on the side of the road really isn't an option.

From the man driving the 5 series on the highway showed in the commercial...

"Changing tires on the road could be dangerous, but with these tires, I don't have to worry about it."
"well, I guess i'll be on my way..."

The concept is to allow you to "drive" the car under 50mph to a safe location for you to wait for the tow truck, fix the tire, replace the tire...etc....

Interestingly, the tirerack tire survey rates the RE050 at the top of their category, and the RE050 RFT at the bottom of their category. The base tire is a pretty good performance tire.

I’m still worried about unsprung weight. Stock wheel/tires weigh 60lbs when they should weigh 40lbs. Half of that is the wheels, half is the tire (+5lbs for RE050, +5lbs for runflat). The base tire is pretty heavy to begin with. All in all, there is too much unsprung weight under there. With stiff sidewalls, the tires don’t stay on the pavement too well.

Quote:

Originally Posted by cincy335i

These sound interesting, but a true test for those of us with the mod bug will be how well do they stick? I really do like the implied safety that the RFT's provide, but when pushed my OEM (i guess 2g RFT's) turn over quicker than a hooker eager to eat the pillow...where as you get no traction from the rear!

Anyways, I hope they addressed the harse ride (the tires not the hooker) and the stickiness of the TIRE. I would love for someone to get these on a car and do some real world testing, some runs at the drag strip and some closed course runs. If the reviews would come in very favorably to non-RFT's then I would be happy to purchase these as replacement tires or at least consider them.

Sorry, but I am not impressed in the least. I'd rather have the best high performance tires than these overpriced compromises. I'm more than happy to change my own tire and then go wherever I please to repair or replace the bad tire. My cynicism leads me to believe that BMW's run-flat strategy is in no small part intended to get owners back to the dealers (on a flatbed) for even things that were once as simple as a flat tire.

I'd give them a try. I live in Canada and would say that RFTs run almost double the price of regular tires not 30% more which really sucks. I think we get hosed badly on tire prices in Canada anyways. I wonder if I could have a pair installed just over the the boarder in Niagara Falls.

At the end of the day, RFTs are not useful in their current form, and in this new form. The price you pay is 20-30% more for a tire that gives you less. The fact of the matter is, on the current 2G tires you cannot drive very far while they are flat, otherwise, as the article state, you cook in the inside lining of the tire and then its useless, and you end up replacing the tire anyways, at the much higher pricepoint. We have gone through about 4 RFTs (Michelin's, not Bridgestone) becuase when they went flat and were driven on (in one case literally driven 300 ft) they were useless because the inner walls started to shave off pieces inside the wheel. I doubt the new tires will fix this issue regardless of whatever new shrinking technology they have.

At the end of the day, the price is too high to pay is too high. Thankfully, I have never experienced a flat tire at highway speeds, but if anyone wants to chime in on what that is like, please do. I switched to regular tires, and I dont think I will ever look back. Mobility kit FTW!

Ive been on conventional tires for about 2 years now, and finally it happened, I had a flat, and not a leak, but a total flat. Within 5 minutes of getting the TPMS warning, the tire was down to 10 psi. I filled it up to 43 psi to try and get back home from the store, and by the time I got home (about 5 minutes) the car was down to 9 psi.

I have no spare thanks to BMW. So in the morning I call for a roadside fix, well, they dont do that and the car had to be towed to my local Discount Tire. No problem you say, and for many, its not. But since I take my 19 month old to day care in the morning, him and I had to stay home and wait for the babysitter to come over, eventually she did and then I had to wait for a taxi to come which took for ever, and take me down to the tire shop. Luckily I had purchased road hazard insurance, and the tire was replaced before I even arrived. Overall, the lack of a spare cost me a ton of headache and time. And luckily, I was home when this happened, just running to get milk at the store. If this had happened far from home and with my son in the car, it would have been quite a mess. How many cabs have childrens seats in them?

I was waiting for improved RFTs so I could switch back, and now I cant wait.

and I really think that run-flats are the future, and that they will one day equip every single car out there. It is really about security and convenience (the majority of women can' t fit a spare and I' d rather have a RFT than having to fit a spare under the rain while wearing a suit).

The only problem with this is that I have never heard of any shop fixing a punctured RFT - they always say you have to replace it. I thought I remembered reading that the shops didn't want the liability because they couldn't tell how far the car had been driven on a flat.

I had a Winter Sport M3 DSST patched last year, no problem. The shop was one of Tire Rack's recommended installers so I'd think they weren't completely clueless.

I don't think this test is adequate. I have used non run flat as well as run flat tires. My own personal experiences with them is that when new, both types of tires gives a good quality ride. However, after couple of weeks, both tires becomes hard. Sometimes they become soft again. I suspected that the brake dust had sometime to do with it. So I wash my tires every 3 days with a paint brush and car wash detergent (the type without the waxing feature). You will notice that the rubber looks darket and feel softer. Now I am able to maintain that new tire comfort ride consistantly. They need to run the test for a month without rain or washing to see if the rubber react with the brake dust. Since they mentioned that the rubber compound is the same as before, the 3G tires might become hard about couple weeks of city driving. Just my 2 cents. But I've been pleaque with this problem for years, and I have gained much from this web site. I just though I register today and share my findings. Doesn't cost much or harm in trying this method. And I'm not selling anything. Hope it will help those who are stuck with a harsh ride.